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12#include <linux/capability.h>
13#include <linux/ctype.h>
14#include <linux/device.h>
15#include <linux/err.h>
16#include <linux/hrtimer.h>
17#include <linux/list.h>
18#include <linux/rbtree.h>
19#include <linux/slab.h>
20
21#include "power.h"
22
23static DEFINE_MUTEX(wakelocks_lock);
24
25struct wakelock {
26 char *name;
27 struct rb_node node;
28 struct wakeup_source ws;
29#ifdef CONFIG_PM_WAKELOCKS_GC
30 struct list_head lru;
31#endif
32};
33
34static struct rb_root wakelocks_tree = RB_ROOT;
35
36ssize_t pm_show_wakelocks(char *buf, bool show_active)
37{
38 struct rb_node *node;
39 struct wakelock *wl;
40 char *str = buf;
41 char *end = buf + PAGE_SIZE;
42
43 mutex_lock(&wakelocks_lock);
44
45 for (node = rb_first(&wakelocks_tree); node; node = rb_next(node)) {
46 wl = rb_entry(node, struct wakelock, node);
47 if (wl->ws.active == show_active)
48 str += scnprintf(str, end - str, "%s ", wl->name);
49 }
50 if (str > buf)
51 str--;
52
53 str += scnprintf(str, end - str, "\n");
54
55 mutex_unlock(&wakelocks_lock);
56 return (str - buf);
57}
58
59#if CONFIG_PM_WAKELOCKS_LIMIT > 0
60static unsigned int number_of_wakelocks;
61
62static inline bool wakelocks_limit_exceeded(void)
63{
64 return number_of_wakelocks > CONFIG_PM_WAKELOCKS_LIMIT;
65}
66
67static inline void increment_wakelocks_number(void)
68{
69 number_of_wakelocks++;
70}
71
72static inline void decrement_wakelocks_number(void)
73{
74 number_of_wakelocks--;
75}
76#else
77static inline bool wakelocks_limit_exceeded(void) { return false; }
78static inline void increment_wakelocks_number(void) {}
79static inline void decrement_wakelocks_number(void) {}
80#endif
81
82#ifdef CONFIG_PM_WAKELOCKS_GC
83#define WL_GC_COUNT_MAX 100
84#define WL_GC_TIME_SEC 300
85
86static LIST_HEAD(wakelocks_lru_list);
87static unsigned int wakelocks_gc_count;
88
89static inline void wakelocks_lru_add(struct wakelock *wl)
90{
91 list_add(&wl->lru, &wakelocks_lru_list);
92}
93
94static inline void wakelocks_lru_most_recent(struct wakelock *wl)
95{
96 list_move(&wl->lru, &wakelocks_lru_list);
97}
98
99static void wakelocks_gc(void)
100{
101 struct wakelock *wl, *aux;
102 ktime_t now;
103
104 if (++wakelocks_gc_count <= WL_GC_COUNT_MAX)
105 return;
106
107 now = ktime_get();
108 list_for_each_entry_safe_reverse(wl, aux, &wakelocks_lru_list, lru) {
109 u64 idle_time_ns;
110 bool active;
111
112 spin_lock_irq(&wl->ws.lock);
113 idle_time_ns = ktime_to_ns(ktime_sub(now, wl->ws.last_time));
114 active = wl->ws.active;
115 spin_unlock_irq(&wl->ws.lock);
116
117 if (idle_time_ns < ((u64)WL_GC_TIME_SEC * NSEC_PER_SEC))
118 break;
119
120 if (!active) {
121 wakeup_source_remove(&wl->ws);
122 rb_erase(&wl->node, &wakelocks_tree);
123 list_del(&wl->lru);
124 kfree(wl->name);
125 kfree(wl);
126 decrement_wakelocks_number();
127 }
128 }
129 wakelocks_gc_count = 0;
130}
131#else
132static inline void wakelocks_lru_add(struct wakelock *wl) {}
133static inline void wakelocks_lru_most_recent(struct wakelock *wl) {}
134static inline void wakelocks_gc(void) {}
135#endif
136
137static struct wakelock *wakelock_lookup_add(const char *name, size_t len,
138 bool add_if_not_found)
139{
140 struct rb_node **node = &wakelocks_tree.rb_node;
141 struct rb_node *parent = *node;
142 struct wakelock *wl;
143
144 while (*node) {
145 int diff;
146
147 parent = *node;
148 wl = rb_entry(*node, struct wakelock, node);
149 diff = strncmp(name, wl->name, len);
150 if (diff == 0) {
151 if (wl->name[len])
152 diff = -1;
153 else
154 return wl;
155 }
156 if (diff < 0)
157 node = &(*node)->rb_left;
158 else
159 node = &(*node)->rb_right;
160 }
161 if (!add_if_not_found)
162 return ERR_PTR(-EINVAL);
163
164 if (wakelocks_limit_exceeded())
165 return ERR_PTR(-ENOSPC);
166
167
168 wl = kzalloc(sizeof(*wl), GFP_KERNEL);
169 if (!wl)
170 return ERR_PTR(-ENOMEM);
171
172 wl->name = kstrndup(name, len, GFP_KERNEL);
173 if (!wl->name) {
174 kfree(wl);
175 return ERR_PTR(-ENOMEM);
176 }
177 wl->ws.name = wl->name;
178 wakeup_source_add(&wl->ws);
179 rb_link_node(&wl->node, parent, node);
180 rb_insert_color(&wl->node, &wakelocks_tree);
181 wakelocks_lru_add(wl);
182 increment_wakelocks_number();
183 return wl;
184}
185
186int pm_wake_lock(const char *buf)
187{
188 const char *str = buf;
189 struct wakelock *wl;
190 u64 timeout_ns = 0;
191 size_t len;
192 int ret = 0;
193
194 if (!capable(CAP_BLOCK_SUSPEND))
195 return -EPERM;
196
197 while (*str && !isspace(*str))
198 str++;
199
200 len = str - buf;
201 if (!len)
202 return -EINVAL;
203
204 if (*str && *str != '\n') {
205
206 ret = kstrtou64(skip_spaces(str), 10, &timeout_ns);
207 if (ret)
208 return -EINVAL;
209 }
210
211 mutex_lock(&wakelocks_lock);
212
213 wl = wakelock_lookup_add(buf, len, true);
214 if (IS_ERR(wl)) {
215 ret = PTR_ERR(wl);
216 goto out;
217 }
218 if (timeout_ns) {
219 u64 timeout_ms = timeout_ns + NSEC_PER_MSEC - 1;
220
221 do_div(timeout_ms, NSEC_PER_MSEC);
222 __pm_wakeup_event(&wl->ws, timeout_ms);
223 } else {
224 __pm_stay_awake(&wl->ws);
225 }
226
227 wakelocks_lru_most_recent(wl);
228
229 out:
230 mutex_unlock(&wakelocks_lock);
231 return ret;
232}
233
234int pm_wake_unlock(const char *buf)
235{
236 struct wakelock *wl;
237 size_t len;
238 int ret = 0;
239
240 if (!capable(CAP_BLOCK_SUSPEND))
241 return -EPERM;
242
243 len = strlen(buf);
244 if (!len)
245 return -EINVAL;
246
247 if (buf[len-1] == '\n')
248 len--;
249
250 if (!len)
251 return -EINVAL;
252
253 mutex_lock(&wakelocks_lock);
254
255 wl = wakelock_lookup_add(buf, len, false);
256 if (IS_ERR(wl)) {
257 ret = PTR_ERR(wl);
258 goto out;
259 }
260 __pm_relax(&wl->ws);
261
262 wakelocks_lru_most_recent(wl);
263 wakelocks_gc();
264
265 out:
266 mutex_unlock(&wakelocks_lock);
267 return ret;
268}
269
